The purpose of this study was to examine the effectiveness of recent irrigant activation methods on cleanliness of the root canals and removal of the smear layer. Materials and Methods:Thirty single-rooted human mandibular premolars with single straight canals were used in this study. Root canals were mechanically prepared using Path files then BT race system till size (#35/0.04). Teeth were randomly divided into 3 groups, according to the irrigatnt activation method used. Control group (conventional irrigation) and two experimental groups according to the method used for irrigant activation in the root canal, EDDY group and XP endo finisher group (n = 10).Then teeth were split vertically to be prepared for SEM examination. The root canals were photomicrographed at magnification of 6000X to assess the presence of smear layer in coronal, middle, and apical thirds. Results showed significant increase of remaining smear layer at the apical third in all groups in comparison to middle and coronal thirds. Eddy and Xp endo finisher succeeded in removal of smear layer specially at the middle and apical third with significant difference than the conventional method without activation. There was non significant difference between Eddy and XP endo finisher in removal of smear layer at the middle and apical thirds. Conclusion: New irrigant activation systems improves the removal of smear layer than the traditional syringe method.